What Is the Difference Between Yams and Sweet Potatoes?

How long should you wait until you get thirds? Should you tell Uncle Walter his teeth fell into the cranberry sauce? How do you find the words to describe Aunt Muriel's stuffing without offending her?

Good questions all, but none are the most pressing on Thanksgiving.

Nope, that honor surely goes to this query: what is the difference between yams and sweet potatoes? You probably use those words interchangeably, like "happy/glad," "attorney/lawyer" or "Pixels/bad movie."

Well, Vox has swooped in to save the day like the dog who eats Aunt Muriel's stuffing to make it look like it was a big hit (what is it with Aunt Muriel's stuffing?).

Yes, there is a difference between a yam -- which hails mostly from West Africa -- and a sweet potato, even though no one seems to realize it. As we learn in this clip, slavery may have played a vital role in bringing the word "yam" to the US. Who knew? Consider yourself thankful to be enlightened this Thanksgiving.